New motor mounts = new vibration.

So im trying to isolate a drive line vibration so after reading many many posts in the old threads I figure I will start with the less expensive things to try to get to the bottom of my vibration issue. Well I installed new motor and trans mounts last weekend and now I have ANOTHER vibration when at idle in gear like when I pull up to a stop sign. When at a stop sign in gear when the rpm's drop to an idle the vibration starts, kinda like a rumble that was not there before. If I put it in park or netural is lessens a lot it mainly when in gear. My other vibration issue is at highway speeds.

Do the motor mounts need to break in or something? Could I have installed them incorrectly? Do they possibly need adjustment?